Circuit interrupter



Aug. 7, 1945. E. E. ARNOLD G IRCUI T INTERRUPTER Filed Jan. '1, 1943 4 Sheets-Sheet l INVENTOR ATTORNEY 7, 1945. E. E. ARNOLD 238L244 CIRCUIT INTERRUPTER Filed Jan'. '7, 1943 4 Sheets-Sheet 2 WITNESSES: INVENTOR gg 2? 0 201775 flr/zaid A? M v l ATTORNE Aug. 7, 1945. E. E. ARNOLD 2,381,244

CIRCUIT INTERRUPTER I Filed Jan. 7, 1943 4 Sheets-Sheet s WITNESSES= INVENTOR BY Zafl. M r ATTORN Aug. 7, 1945. E. E. ARNOLD j 2,381,244

CIRCUIT INTERRUPTER 'Fiied Jan. 7, 1943 4 Sheets-Sheet 4 WITNESSES: INVENTOR I Edwin E/lrnold.

' ATTORNE Patented Aug. 7, 1945 time om'reo s ATEs PATENT orrrce CIRCUIT! INTEBRUITEB 'Etlwin E. Arnold, Pittsburgh, Pa... usslgnor to Westinghouse Electric fiorporatlon, East litts- Eburgh, Pa.., a corporation of Pennsylvf Application January 1, 1943, Serlel No. 471,555

20 Claims.

This invention relates to circuit interrupters in general end, more particularly, to are extinguishing structures and operating mechanisms therefor.

More particularly, it is on object of my in.- ventlon to efiect rapid orc extinction by utilizing a pump means actuated by ot leest a por= tion or the series current passing through the interrupter. v I

Another object of-rny invention is to provide on improved circuit interrupter having improved and more effective contact structure.

.Anotlier object is to provide on improved circult interrupter herring e, plurality of contest members and connecting iiuirl moving means electrically between two of the contact members.

Another object is to orovide on improved cir cult interrupter comprising e plurality of con tact members which sensrete seoguentlelly clur ing opening ope ation or the interrupter, one electrically connect :1 fluid moving means between two or the contact members to force can orc extinguishing iluiri through the are which is shown during the orerotion to eiiect the extinction thereof.

A more species oioject oi" my invention is to provide improved circuit interrupter having three contact n'iemsers engeglngeecli other in eloutting relation in the closed circuit position. A iiuicl moving means is electricslly connected between two of the contest members, and the third: contact rnemlzer is opereble to draw on are which is rapidly quenched by the operation the flute moving means.

Another object to provide an improved con tact structure in. which the intermediate con toct' is flexibly su sorted on o flexible clinrliregrn. The diaphragm be employed during the opening operation of the interrupter to effect initial fluid motion to extinguish the arc drown. The arrangement is especially cle'- during the interruption of low currents.

Another object is provide an improved are I oirclt interrupter having means actuated icy at extinguishing unit in which :2. coil is connected in series circuit during the opening operation to more a. ring-shaped piston to efiect fluid mo= tion for, the extinction of lie are drawn dur ing the opening operation 62 the interrupter. Preferably the contact structure is so arranged that the coil is not shortedout during the elongation of the are drawn during the opening op eration. 7

Another object to provide on ere extinguishing unit with an improvedoneroting moons ior the movable contact structure.

A further object is to provide an improved. arc extinguishing assemblage comprising a, plurality of arc extinguishing units, each of which has improved operating means, the arrangement being such that the moving contacts in all of shield Mo, which else iormn= the ercextingulsliing units ere cctueted taneously.

A .iurtlier object is to orovlrle on improved simullesst a portion oi the series current to efiect renirl closure oithe contsct structure during a closing operation with voltage on the Further objects end edventeges will readily become apparent upon at reading of the fol1ow-' trig description token in conjunction with the drawings in which:

Figure l is on elevstionel view, portiolly' in section, of e. complete circuit interrupter emlooclying my invention, the interrupter lce'mg shown in the closed-circuit position;

Fig. 2 is an enlarged elevetionel vies. in sec tion of top are extinguishing shown in l, the interrupter being in the elosemclr cult position;

Fig. 3 is o view similar to 2 ing the interrupter in open=circuit pontion;

is e vies-7 in cross section taken on the line W"l oi lg to the ell-swings in nor icnler to l, the reference numeral l tank filled to level 2 with 2. suitable extinguishing fluid, in instenceoil. see t enties. from the cover 3 tenl: i two G, eecli hauling attached lower enrl orc entinguisliii "r by the G.

A conducting bridg ng, "l Yrs imuletingreal 0 1" ion. glturllnsl nut: in. s res tricelly connect the bleg'es in the closed as shown in l each ere 6 prises plurality, in see 'lEEE,

extinguishing units oe reference numeral 9. eiztlngur ng units :3

eseemologe G is on.

ion, end

tion.

It will, therefore, ice senescent the slice tricel circuit through the interrupter passes through a terminal conductor located centrally withinthe insulating bushing 51, not shown, to the upper arc extinguishing unit whence the circuit passes through the intermediate ere ex tinguishing unit it to the lower ere extinguishing.

unit ii. The circuit then extends through the conducting bridging member I to the right-hand arc extinguishing assemblage 8 to the other line terminal of the interrupter.

\ tionary contact I! having an annular arc-resistcontact 23 guided in its reciprocal longitudinal contact 21 to the open'circuit position. I 6

"observed thereiore that the laterali shows the upper arc extinguishing unit 9 it will be observed that the upper arc extinguishing unit I comprises a top metallic dome it which is se- 10 cured, as by the stud bolts II, to an insulating toppiate II and to an insulating casing II. The insulating top plate ll supports an annular staing portion ll composed oi a suitable'arc resisting material. Making contact with the annular arc-resisting portion ID in the closed-circuit position oi the interrupter is a nozzle-shaped intermediate contact I! having an upper annular arcresisting portion which engages the annular arc-resisting portion ll of the stationary contact I l in the closed-circuit position of the interrupter as shown in Fig. 2. t i V The nozzle-shaped intermediate contact is is resiliently supported by a flexible metallic diaphragm II. The outer periphery of the metallic diaphragm II is rigidly secured to the insulating casing It. Cooperating witha lower annular arc-resisting portion 22 of the nozzle intermediate contact I8 is a rod-shaped lower movable motion by an insulating guide member 24. The lower end of the movable contact 23 is in this in- .stance enlarged to form a substantially square block member 25. The block member 25 is connected by a pin it to two links ILthe other ends of which are pivotally connected by a knee pin II to two actuating link members 2! and to two link members ll. The lower ends of the-two link members III are pivotally supported by the pin 1 i A -bell crank 31 pivotally mounted on the pivot pin it and pivotally connected by the pivot pin Ila to the links it has a bifurcated portion-l4 to which is pivotally mounted by the pin 35 the insulating operating rod R. It will, consequently, 4:, be seen that downward motion or the insulating operating rod l2 results in clockwise rotation of the bell crank 32 about the pivot pin II to result in the two actuating link members 29 being moved toward the right to break the toggle comprising the links Il, Iii to effect a downward movement of the movable contact II. The position of the various structural parts in' the open circuit position is more clearly shown in Fig. 3, Fig. 2 showing the position of the parts in the closed-circuit position of the interrupter.

A compression spring 38 biases the bell crank "in aclockwise direction as viewedin Fig. 2, which biasing action tends to move the movable A plurality, in this instance two, roller members 81 positioned in recesses formed in the block member 28 roll along a vertical surface 38 provided by the lower metailic casting 39; It will be a stress on the 05 blockmember Il-lscting toward the left during the closing of theinterrupter is relieved by the roller members 11 rollingalong the vertical surface ll. Consequently, the aperture It provided in guide member 24 is not d formed to result in. a leakage of fluid adjacent the upper end of the movable contact II through the aperture 40 and out of the arcing chamber,

generally designated by the reference numeral C l.'

The lower metallic casting II is clamped-by 15 {downward movement of the rod II the conducting bridging member 1 remains in contact with the disconnect fingers II associ 0 ated with the lower arc extinguishing units 8.

means thestud; bolts 4! to the insulating'casing II. The stud bolts 42 also secure a lower insulating member ll to the insulating casing It. Rigidiy positioned within a recess 44 provided in the lower insulating member a is a repulsion coil 4| composed ofan insulation-covered metallic conductor wound in a spiral manner or pan cake coil. One end of the revulsion coil II is connected by the conducting strap ll to the metallic diaphragm ii and hence to the nozzle shaped intermediate contact It. The other end of the repulsion coil ll is connected by the conducting strap i! to the stud bolt i4 and hence electrically to the metallic dome member II. The annular stationary contact I! is connected electrically by a strap 48 to the bolt ll and thence by means of the conducting strap to to the stud bolt 14.

It will, consequently, be apparent that the repulsion coil 45 is connected between the annular stationary contact I! and the nozzle-shaped zlntermediate contact it. Positioned immediately above the repulsion coil! is a ring-shaped conducting plate 5! biased downwardly by the compression springs 82 and secured to a metallic piston n. It will be hereinafter explained, that upon energization oi the repulsion coil ll the ring-shaped plate II will be forcibly repelled upward against the biasing action of the compression springs 52 to put the fluid within the arcing chamber 4i under pressure. permit unimpeded motion of the ring-shaped plate II and the piston 53.

In the closed-circuit position of the interrupter,

as shown in Fig. 2, the electrical circuit there-,

through comprises the metallic dome casting it, stud bolt ll, conducting strap 6., bolt is, conducting strap annular stationary contact ll, intermediate contact I, movable contact 23,

block member 2!, bolt b8, conducting strap IT to the bolt I of the intermediate arc extinguishing unit 9, from whence the circuit passes in an identical manner therethrough to the lower arc extinguishingnnit 8 (refer to Fig. 1).. The electrical circuit passes from the conducting strap 81 associated withthe lower arc extinguishing unit 8 of Fig. 1 to the disconnect fingers II which make engagement in the closed-circuit position at the interrupter, as shown, with the movable conducting bridging member 1.

The opening operation of the interrupter will now be described. During the opening operation the insulating lift rod I is moved downwardly by suitable operating mechanism not shown to permit downward motion of the insulating operating rod 12, the latter being biased downwardly by the compression springs 38. During the insulating operating The downward movement of the insulating operating rod l2 causes a clockwise rotation of the bell cranks II to result in the downward move- -ment or the movable contacts 23 in a manner previously described. It will therefore be apparent that the initial downward movement of the insulating operating rod I! caused a simultaneous downward movement of the respective movable contacts I! associatedjvvith the several arc extinguishing units I. .g

The-initial downward movement of the movable contacts 23 causes a separation between the stationary contacts I! and the intermediate contacts I. as shown more clearly by the dotted lines in Fig. '3. The separation between the stationary Vents I4 and II- 'ble contact so contact ii and the intermediate contact l9 cuit passes in an identical manner as that previously described through the two lower are extinguishing units 9 to the disconnect fingers t and to the conducting bridging member i. The circuit passes through the righthand arc extinguishing assemblage (see Fig. 1) in an identical manner to the right-hand line terminal of the interrupter When the stationary contact ll separates from the intermediate contact it and the repulsion coil dd is consequently put in series circuit, the ring-shaped plate has induced therein an alternating current which is substantially 180 electrical degrees out of phase with the alternating current passing through the repulsion coil lli. The induced current in the ring-shaped plate 5i causes it to be violently forced upward against the biasing action of the compression springs 52 to Zorce the piston upward and hence to put the fluid within the arcing chamber ll under'pi'essure. It will also be observed that during this time the diaphragm in has moved downward and hence has also tended to put the fluid within the arcing chamber ill under pressure. Consequently, by the time the movafrom the intermediate contact it, a i'oiceiui jet oiere extinguishing fluid, in this instance oil, washes across the top surface of the movable contact it to extinguish the are which is drawn between the movable contact 23 and the intermediate contact is and which is designated by the reference numeral 59 in Fig. 3. v

Conse uently the pressure of the fluid within the arcing chamber ii causes a flow of fluid upward through the noazie shaped intermediate contact is to effect the rapid extinction of the arc When the is extinguished the circuit through the interrupter is broken and the compression springs return the ring-shaped plate at to its lower position adjacent the repulsion coil 35. After the electrical circuit is broken through the interrupter the conducting bridging member l separates from the disconnect iingers dil- (see Fig. l.) to introduce two isolating gaps in the circuit.

It will be observed that during the interrup tion of high short-circuit currents the consev upward to put the'fluid within the arcing chamdownward movement of the diaphragm 2! dis- .places'roughly 15% of the fluid displaced by the piston 53. This displacement of the fluid caused by the downward movement of the diaphragm 2| is independent of the current value and is, as mentioned previously, useful for interrupting low-value currents where the repulsion coil is not so effective.

It will be observed that during the closing operation of the interrupter with voltage on the line the movable contact 23 will move upward to strike the intermediate contact l9 tocause.

the insertion of the repulsion coil 45 in series circuit before the intermediate contact It strikes the stationary contact ll. Thus during the closing operation the repulsion coil 45 will be energized and will repel the ring-shaped plate iii ber 4i under pressure. This sudden rise in pressure during the closing operation will flex the diaphragm 2i upward to increase the upward speed of the intermediate contact it and hence to increase the speed with which the intermedi ate contact it approaches the annular stationary contact ill. Consequently, I have used a means utilizing a art of the energy passing through the interrupter to speed up the closing pf the contact structure during a closing operation with voltage on the line. When the intermediate contact it strikes the stationary contact ll during the closing operation, the repulsion coil will be shorted out, and the ring-shaped plate 5i will be forced to its lower position by the compression springs The interrupter will then be in the closed-circuit position as shown in Fig. 2, and the ring-shaped plate El will be at its lower position ready for the next opening operation.

It will be observed that the intermediate contact ill has an upstanding portion (it, which in ;'this instance extends completely through the annular stationary contact ll. The upstanding portion til is provided so that the arc which is drawn during the opening operation, will not quent repelling action between the repulsion coil chamber ll under pressure to effect the inter-' ruption of the are it during the interruption of 10W currents. As shown in the drawings, the

be blown through the intermediate contact ill to have its upper terminal reach the stationary contact ill. If this occurred the repulsion coil d5 would be shorted out and hence would be rendered ineffective. Consequently, by providing the upstanding portion til the are 59 is prevented from contacting the stationary contact ill and short- H ing out the repulsion coil Vents iii in the plate it permit free movement of the diaphragm El.

It will be observed that immediately above the diaphragm 2i is an annular surface iii. The annular surface 60 has a twofold purpose. First it ofiers support and safety against overstressing the diaphragm 2i. Secondly, the contour of the surface 6! is such as to follow the natural deflection curve of the diaphragm 2i loaded uniformly, that is, from the hydrostatic oil pressure on the inner surface of the diaphragm 2 i. Such a deflection curve for a given total uniform loading is flatter and of less maximum amount at the center of the diaphragm 2| than would result from the same total load being applied at the center of the diaphragm H, The result of this design provision is that contact may not be made between the stationary contact ill and the intermediate contact l9 and therefore the repulsion coil it may not be shorted out by pressure alone, but will require additional pressure applied at the center of the diaphragm H by the moving contact 23 to effectthe flnal contact between the intermediate contact l9 and the stationary contact l1.

As mentioned previously, when the interrupter is used on alternating current the induced current in the ring-shaped plate is substantially 180 electrical degrees out of phase with the current through the repulsion coil 45. This difference in phase produces a violent repellent action between the coil 45 and the plate 5!. When the interrupter is used on a direct current circuit the increase in current through the coil 45 will also induce a current through the plate 5| to efiect a similar repelling action, although of not as long duration as in the casepf an alternating current circuit. However, it is to be clearly understood that my invention is applicable not only to alternating current circuits but to direct current circuits as well. Furthermore, it is to be understood that in place of the repulsion coll 45 and the piston 53 secured to the plate 51, I may use other fluid moving pump arrangements actuated by at least a portion of the series current through the interrupter. By my show-- ing only a particularform of electrically actuated fluid moving means, it is not to be understood that my invention is limited to the particular form shown. Other fluid moving means, such as, forexample, a solenoid pump arrangement may be used in place of repulsion coil 45.

Although I have shown an application of my invention associated with a liquid-type circuit interrupter, it is to be; clearly understood that my invention may be applied to other types of circuit interrupters, such as those operating in a gaseous medium or even in air. The term fluid as used herein and inthe appended claims comprises liquids, vapors, gases and sprays.

Although I have shown a specific form of circuit interrupter, it is to be clearly understood that the same was merely for the purpose of illustration and that changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. In a circuit interrupter, a first relatively stationary contact member, a second intermediate contact member, a third movable contact member, means resiliently mounting the second intermediate contact member, the three contact members engaging each other in abutting relation in the closed circuit position of the inter- .rupter, a fluid moving means electrically connected between the first relatively stationary contact member and the second intermediate contact member, and means for causing the separation of the three contact members to insert the fluid moving means in series circuit.

2. In a circuit interrupter, a first relatively stationary contact member, a second intermediate contact member, a third movable contact member, means resiliently mounting the second intermediate contact member, the three contact members engaging each other in abutting relation in the closed circuit position of the interrupter, a

contact member, a third movable contact member, means resiliently mounting the second intermediate contact member, the three contact members engaging each other in abutting relation in the closed circuit position of the interrupter, a fluid moving means electrically connected between the first and second contact members, and means for causing the sequential separation of the three contact members to insert the fluid moving means serially in the circuit before the subsequent separation of the second and third contact members, an arc being drawn upon the separation of the second and third contact members, the fluid moving means helping to extinguish the arc.

4. In a circuit interrupter, a first contact member, a second contact member, a third contact member, the three contact members engaging each other in abutting relation in the closed circuit position of the interrupter, a fluid moving means electrically connected between the first and second contact members, andmeans for causing the sequential separation of the three contact members to insert the fluid moving means serially in the circuit before the subsequent separation of the second and third contact-members, an are being drawn upon the separation or the second and third contact members, the fluid moving means helping to extinguish the arc, the second contact member being formed as a nozzle to shield the first contact member from the arc.

5. In a circuit interrupter, a first contact member, a second contact member, a third contact member, the three contact members engaging each other in abutting relation in the closed circuit position or the interrupter, a fluid moving means electrically connected between the first and second contact members, and means for causing the sequential separation of the three contact members to insert the fluid moving means serially in the circuit before the subsequent separation of the second and third contact members, an are being drawn upon the separation of the second and third contact members, the fluid moving means helping to extinguish the arc, the second contact member being formed as a nozzle to shield the first contact member from the arc, the second contact member being supported on a flexible diaphragm.

6. In a circuit interrupter, a first contact member, a second contact member, a third contact member, the three contact members engaging each other in abutting relation in the closed circuit position of the interrupter, a fluid moving means electrically connected between the first and second contact members, and means for causing the sequential separation of the three contact members to insert the fluid moving means serially in the circuit before the subsequent separation of the second and third contact members, an are being drawn upon the separation of the second and third contact members, the fluid moving means helping to extinguish the arc, the second contact member being formed as a nozzle to shield the first contact member from the arc, the second contact member being supported on a flexible diaphragm, the flexible diaphragm being arranged to cause additional fluid motion.

7. In a circuit interrupter, a substantially enclosed arcing chamber having one wall thereof formed by a metallic diaphragm, an annular relatively stationary contact, an intermediate contact flexibly mounted on the metallic diaphragm, and a movable rod-shaped contact movable within the arcing chamber which forces the intermediate contact against the stationary con tact in the closed circuit position of the interrupter.

8. In acircuit interrupter, a substantially enclosed arcing chamber having one wall thereof formed by g metallic diaphragm, an annular relatively stationary contact, a nozzle-shaped intermediate contact flexibly supported on the metallic diaphragm, and a rod-shaped movable contact movable within the arcing chamber and operable to forcethe intermediate contact in abutting relation with the stationary contact in the closed circuit positionof the interrupter.

9. In a circuit interrupter, an annular relatively stationary contact, an intermediate contact having a nozzle portion which extends at least part way through the annular stationary contact in the closed circuit position of the interrupter, a movable contact which engages the intermediate contact in the closed circuit position to force the latter against thestationary contact.

10. In a circuit interrupter, a substantially enclosed arcing chamber having one wall thereof formed by a metallic diaphragm, an annular relatively stationary contact, an intermediate contact having a nozzle portion which extends at leastpart way through the annular stationary contact in the closed circuit position of the interrupter, a movable contact movable within the arcing chamber which engages the intermediate contact in the closed circuit position to force the latter against the stationary contact, the intermediate contact being flexibly supported on the metallic diaphragm.

11. In a circuit interrupter, an annular relatively stationary contact, a nozzle-shaped intermediate contact fiexibly supported on a metallic diaphragm, a movable rod-shaped contact cooperating'with the intermediate contact to establish an are, a repulsion coil connected between the stationary and intermediate contacts, and an annular piston ring operable upon energization of the repulsion coil to cause fluid motion through the nozzle-shaped intermediate contact to effect the extinction of the arc.

12. In a circuit interrupter, an annular relatively stationary contact, a name-shaped intermediate contact flexibly supported on ametallic diaphragm, a movable rod-shaped contact cooperating with the intermediate contact to establish an arc, a repulsion coil connected between the stationary and intermediate contacts, and an annular piston ring operable upon energization pf the repulsion coil to cause fluidmotion through the nozzle-shaped intermediate contact to eifect the extinction of the arc, the diaphragm being operable to eifect additional fluid motion through the nozzle-shaped intermediate contact to effect quick extinction of the are on low current interruption. y

13. In a circuit interrupter, a substantially enclosed arcing chamber having one wall thereof formed by a metallic diaphragm. an annular relatively stationary contact, an intermediate contact flexibly mounted on the metallic diaphragm, and

arcing chamber which forces the intermediate contact against the stationary contact in theclosed arcing chamber having an annular stationary contact forming an outlet, an annularlyshaped intermediate contact flexibly supported on a diaphragm, and a movable contact operable to force the intermediate contact against the stationary contact in the closed circuit position of the interrupter.

15. In a circuit interrupter, a substantially closed arcing chamber having-an annular stationary contact forming an outlet, an annularlyshaped intermediate contact flexibly supported on a diaphragm, a movable contact operable to force the intermediate contact against the stationary contact in the closed circuit position of the interrupter, and a fluid moving means electrically connected between the stationary and intermediate contacts.

16. In a circuit interrupter, a substantially closed arcing chamber having an annular rela- I a movable rod-shaped contact inovable within the tively-stationary contact forming an outlet, a nozzle-shaped intermediate contact which extends at least part way through the annular stationary contact in the closed circuit position of the interrupter, a flexible diaphragm, the intermediate contact being flexibly supported on the diaphragm, and a movable contact operable to force the intermediate contact against the stationary contact in the closed circuit position.

1'7. In a circuit interrupter, a substantially closed arcing chamber having an annular relatively stationary contact forming an outlet, a nozzle-shaped intermediate contact which extends at least part wayvthrough the annular stationary contact in the closed circuit position of the interrupter, a flexible diaphragm, the intermediate contact being flexibly supported on the diaphragm,.a movable contact operable to force the intermediate contact against the stationary contact in the closed circuit position, and a fluid moving means electrically connected between the stationary and intermediate contacts.

18. In a circuit interrupter, a flexible diaphragm, a substantially closed arcing chamber having one wall thereof formed by the diaphragm, an annularly-shaped intermediate contact supported by the diaphragm, a stationary contact, amovable contact movable into the arcing chamber to force the intermediate contact into engage= ment with the stationary contact in the closed circuit position.

19-1:1 a circuit interrupter, a flexible 'diaphragm, a substantially closed arcing chamber having one wall thereof formed by the diaphragm, an annularly-shaped intermediate contact supportedby the diaphragm, a stationary contact, a movable contact movable into the arcing chamber to force the intermediate contact into engagement with the stationary contact in the closed circuit position, and a fluid moving means electrlcally connected between the stationary and m termediate contacts. a

20. In a circuit interrupter, means for establishing an arc, fluid moving means for moving.

fluid to help extinguish the are, energy storing means for storing energy during the closing operv ation. the stored energy, being used during the Enwm n. ARNOLD. 

